Ireland can only beat what’s put in front of them and the manner in which this relatively inexperienced side dominated proceedings from start to finish can’t be ignored, but there would be a lot more to gain from a sterner test.

They may well get that in Tokyo next Saturday as Japan respond after a poor display which shows the magnitude of the task facing Jamie Joseph as he prepares to whip them into shape to host the 2019 Rugby World Cup.

Another drubbing by an understrength Irish team next Saturday would suggest Joe Schmidt’s team will encounter few difficulties when these two sides meet at the pool stage in the RWC in two years, and that’s the last thing the Irish coach would want to take away from this tour.

And while the likes of Niall and Rory Scannell, Jack Conan, Dan Leavy and John Ryan bolstered their burgeoning international careers with stellar displays in front of a crowd of 27,381 at a venue which will be used for the 2019 RWC, it was the display of one of the old-stagers who lifted the Ecopa Stadium.

Keith Earls crossed twice to beat Denis Hickie’s 2003 record of eight international tries in a season for Ireland. Ireland have scored 16 tries on this tour, Earls has got four of them and was the key man in at least half of the other dozen.

The crowd on Saturday — bolstered by thousands of schoolkids, all clad in white shirts, black trousers/skirts, who were given the afternoon off from class — came to see the home No. 11 in action. In fairness, Kenki Fukuoka is some operator and, as Schmidt noted afterwards, it’s not often you see Simon Zebo burned on the outside, but the Japanese struggled to bring their 24-year old star into an effective role.

Instead, it was the visiting No. 11 who dominated, with Earls class in everything he did, making his continued Lions omission baffling - not least at a time when relative unknowns are being drafted on the basis they are close at hand.

Earls is a 12-hour flight away from Lions action, scarcely out of range but seemingly out of sight while there are plenty of Welsh and Scot reinforcements conveniently close at hand in New Zealand.

“It’s something I don’t have any control over,” said Schmidt. “Selection for the Lions are their prerogative and they have made some decisions around geographical proximity. Some of our players are certainly enjoying the experience they are having here and they will stay focused but if they do get a late call up that would be fantastic for them as well.

“It’s not for me to anticipate others selections. We keep it very Ireland focused. I know Earlsey is incredibly proud every time he plays for Ireland. That’s apparent about the way he goes about his work, we saw it last week, we saw it today He’s in great form.”

Ireland supporters in good voice during the Test match against Japan in Shizuoka. Picture: Brendan Moran

Schmidt’s main priority now is to keep players focused for the final week of a long season and ensure that they are prepped to deal with what Japan throw at them, and he fully expects a reaction from their wounded hosts.

“They will feel they can take us. The speed they moved the ball, the speed of the footwork of some guys, I thought we got a really good workout defensively.

“There was a period in the first half where we took them from five metres off our own line to 25 metres off our line. The way the lads got back up, got off the line I thought was really impressive.

“As much as we scored a number of tries, while we conceded the three, we defended well.”

The number of debutants on this tour rose to seven — Ulster bound scrum-half John Cooney is the only uncapped player left in the party — with Leinster winger Rory O’Loughlin and Ulster lock Kieran Treadwell both making their bows off the bench.

The sin-binning of Japan tighthead Heiichiro Ito afer 24 minutes gave Ireland the opening they needed to ensure that their 100% record against the Brave Blossoms continued for a sixth test.

Ireland, with Earls having got his first try after 12 minutes, blasted the Japanese when they had the extra man, chalking up 21 points in that time with Leavy powering over for a brace and Conan getting the first of two to leave it 31-3 at the interval, with Paddy Jackson kicking flawlessly throughout.

Ireland notched 341 metres with the ball to Japan’s 95 in that period, and while the eventual figure tapered out at 608 to 425 metres, the outcome was never in doubt as Ireland won by more than double scores for the fifth time in their sixth meetings. This was their fourth biggest win over Japan.

Conan grabbed his second after the restart and while Japan responded with a good try from full-back Ryuji Noguchi, Garry Ringrose and Earls responded for Ireland.

Late tries from Fukuoka and Yutaka Nagare won’t be unhelpful in keeping the visitors focused this week, but by the second of the tries, Ireland were down to 14 with Luke McGrath off with blurred vision after the bench was emptied.

Schmidt said he doesn’t expect any of the players who picked up injuries —Zebo (knee), Jackson (shoulder), Finlay Bealham (facial cut and shoulder), McGrath (eye), Leavy (head stitches), Rhys Ruddock (passed HIA) and Cian Healy (shoulder) — to be ruled out of next Saturday’s final test.